WASHINGTON —The Arizona tragedy that left six people dead and a respected congresswoman critically wounded has Washington — and the nation — reflecting on an increasingly toxic political climate and calling for change.

"It's a moment for both parties in Congress to come together," Florida Rep. Debbie Wasserman Schultz said Sunday on Meet the Press. "We absolutely have to realize that we're all in this for the same reason, to make America a better place."

House Speaker John Boehner said during a conference call that it was an occasion to "lock arms, both in condemnation of this heinous act, and in prayer for those killed and wounded in this attack. At a time when an individual has shown us humanity at its worst, we must rise to the occasion for our nation and show Congress at its best."

In that spirit, Republican leaders delayed what promised to be a contentious vote Wednesday on the repeal of the new federal health care law, and instead will take up a resolution honoring Democratic Rep. Gabrielle Giffords and the other victims in the shooting in Tucson on Saturday.

While much is still unknown about the shooter's motives, it has pushed to the forefront the ongoing debate about whether American political commentary has descended into reckless demagoguery with tragic consequences.

The debate over health care over the past year spawned some of the hardest feelings, with mass protests outside the Capitol, displays of firearms at political rallies, heated words at town hall meetings and threats of violence against lawmakers, including Giffords.

The shooting in Arizona made it clear that those threats are not to be taken lightly.

"I think everybody's going to be cautious," Rep. Kathy Castor, D-Tampa, said in an interview Sunday. But she added: "I'm going to continue to be a very active and outgoing congresswoman. I don't think Gabby would want us to do anything else."

Castor said the vitriol has grown markedly since she was elected in 2006. "It's become very personal," she said, adding that the poor economy is a factor.

"You add in radio talk show hosts that play on people's economic insecurities and place personal blame on certain political leaders and it's inflamed the rhetoric," Castor said.

"I think there's going to be a great deal of reflection, especially as we approach Dr. Martin Luther King's birthday," she said.

Rep. Steve Southerland, a newly elected Republican from Panama City, said it would be wrong to slide blame away from the man charged in the shooting, 22-year-old Jared Lee Loughner.

"This young man bears the responsibility for the pain he has inflicted," Southerland said.

But he said a spirited debate, while necessary, should be civil. "We can disagree without being disagreeable, without violating personal respect."

Southerland had a chance meeting with Giffords on Thursday just off the House floor.

"I walked by and she extended her hand to me and said, 'Hi, I'm Gabby Giffords, and I think you're a new freshman.' " Giffords introduced Southerland to some House staffers.

"She just had an infectious personality," Southerland said. "When I learned it was her that was attacked, my heart just sank."

Calm is sure to prevail in Washington this week, but the question is, how long will it last? Previous tragedies, including the Oklahoma City bombing, were met with strenuous calls for cooler heads but divisiveness eventually returned.

A return to the health care debate will be a key test. So far, House leaders have not said when the repeal effort would be restarted. It is a mostly symbolic move, given that Democrats still control the Senate and can block action.

The long-term prospects for a greater level of civility face a few challenges, however.

The November election cleared away moderates in both parties, leaving sharper partisan divisions.

There are now few Democrats who represent areas won by Republican John McCain in the 2008 presidential election (Rep. Allen Boyd, a long-serving Democrat, was one of them before he was defeated by Southerland), and few Republicans in districts won by Barack Obama.

"There are far fewer brokers of compromise," said David Wasserman, who analyzes House elections for the nonpartisan Cook Political Report. "It's a Darwinian evolution, and that creates a very difficult working environment for both sides."

There are also round-the-clock news media that thrive on conflict and increasingly sophisticated — and caustic — political advertising.

In the immediate aftermath of the shooting, commentators were already starting to place blame. Some criticized Sarah Palin, who in the past election put together a list of Democrats she wanted her supporters to defeat, using crosshairs on a map to identify the targets. Giffords was among them.

Palin has said violence was never the intent and issued a statement of sympathy Saturday.

Others have pointed fingers at the tea party movement, which loudly protested the health care legislation last year. But conservative leaders accused liberals of trying to exploit a tragedy for political gain.

"Violence is intolerable, be it from the left or right," said Everett Wilkinson, a tea party leader in South Florida. "Our hope is that this heinous act will effect a positive change between the interaction between elected officials and their constituents."

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For now, the mood is decidedly sober, if still tinged with a whiff of partisanship, as two views from Sunday's Meet the Press illustrated:

"We are in a dark place in this country right now,'' said Rep. Emanuel Cleaver, D-Mo. The atmosphere is so "toxic,'' he said, "that people come to Washington, they come to the (congressional) gallery, and they feel comfortable in shouting out insults. … We had someone removed last week shouting out some insult about President Obama's birth. I think members of Congress either need to turn down the volume, begin to try to exercise some high level of civility, or this darkness will never ever be overcome with light."

Republican Rep. Raul Labrador of Idaho argued that this is not new and not the fault of any one side.

"During the Bush administration, we had a bunch of people on the left who were using the same kind of vitriol that some people on the right are using now against Obama," he said. "So it's not something that either party is guilty by themselves or either party is innocent of. And we have to make sure that we take care of it."

Alex Leary can be reached at leary@sptimes.com. Follow him on Twitter @learyspt.